src/transport/transport_api.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2009 Christian Grothoff (and other contributing authors)
   4
   5      GNUnet is free software; you can redistribute it and/or modify
   6      it under the terms of the GNU General Public License as published
   7      by the Free Software Foundation; either version 2, or (at your
   8      option) any later version.
   9
  10      GNUnet is distributed in the hope that it will be useful, but
  11      WITHOUT ANY WARRANTY; without even the implied warranty of
  12      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13      General Public License for more details.
  14
  15      You should have received a copy of the GNU General Public License
  16      along with GNUnet; see the file COPYING.  If not, write to the
  17      Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18      Boston, MA 02111-1307, USA.
  19 */
  20
  21 /**
  22  * @file transport/transport_api.c
  23  * @brief library to access the low-level P2P IO service
  24  * @author Christian Grothoff
  25  */
  26 #include "platform.h"
  27 #include "gnunet_client_lib.h"
  28 #include "gnunet_arm_service.h"
  29 #include "gnunet_hello_lib.h"
  30 #include "gnunet_protocols.h"
  31 #include "gnunet_server_lib.h"
  32 #include "gnunet_time_lib.h"
  33 #include "gnunet_transport_service.h"
  34 #include "transport.h"
  35
  36 /**
  37  * After how long do we give up on transmitting a HELLO
  38  * to the service?
  39  */
  40 #define OFFER_HELLO_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
  41
  42 /**
  43  * After how long do we automatically retry an unsuccessful
  44  * CONNECT request?
  45  */
  46 #define CONNECT_RETRY_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 750)
  47
  48 /**
  49  * How long should ARM wait when starting up the
  50  * transport service before reporting back?
  51  */
  52 #define START_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
  53
  54 /**
  55  * How long should ARM wait when stopping the
  56  * transport service before reporting back?
  57  */
  58 #define STOP_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
  59
  60 /**
  61  * Entry in linked list of all of our current neighbours.
  62  */
  63 struct NeighbourList
  64 {
  65
  66   /**
  67    * This is a linked list.
  68    */
  69   struct NeighbourList *next;
  70
  71   /**
  72    * Active transmit handle, can be NULL.  Used to move
  73    * from ready to wait list on disconnect and to block
  74    * two transmissions to the same peer from being scheduled
  75    * at the same time.
  76    */
  77   struct GNUNET_TRANSPORT_TransmitHandle *transmit_handle;
  78
  79   /**
  80    * Identity of this neighbour.
  81    */
  82   struct GNUNET_PeerIdentity id;
  83
  84   /**
  85    * At what time did we reset last_sent last?
  86    */
  87   struct GNUNET_TIME_Absolute last_quota_update;
  88
  89   /**
  90    * How many bytes have we sent since the "last_quota_update"
  91    * timestamp?
  92    */
  93   uint64_t last_sent;
  94
  95   /**
  96    * Quota for outbound traffic to the neighbour in bytes/ms.
  97    */
  98   uint32_t quota_out;
  99
 100   /**
 101    * Set to GNUNET_YES if we are currently allowed to
 102    * transmit a message to the transport service for this
 103    * peer, GNUNET_NO otherwise.
 104    */
 105   int transmit_ok;
 106
 107   /**
 108    * Set to GNUNET_YES if we have received an ACK for the
 109    * given peer.  Peers that receive our HELLO always respond
 110    * with an ACK to let us know that we are successfully
 111    * communicating.  Note that a PING can not be used for this
 112    * since PINGs are only send if a HELLO address requires
 113    * confirmation (and also, PINGs are not passed to the
 114    * transport API itself).
 115    */
 116   int received_ack;
 117
 118 };
 119
 120
 121 /**
 122  * Linked list of requests from clients for our HELLO
 123  * that were deferred.
 124  */
 125 struct HelloWaitList
 126 {
 127
 128   /**
 129    * This is a linked list.
 130    */
 131   struct HelloWaitList *next;
 132
 133   /**
 134    * Reference back to our transport handle.
 135    */
 136   struct GNUNET_TRANSPORT_Handle *handle;
 137
 138   /**
 139    * Callback to call once we got our HELLO.
 140    */
 141   GNUNET_TRANSPORT_HelloUpdateCallback rec;
 142
 143   /**
 144    * Closure for rec.
 145    */
 146   void *rec_cls;
 147
 148   /**
 149    * When to time out (call rec with NULL).
 150    */
 151   struct GNUNET_TIME_Absolute timeout;
 152
 153   /**
 154    * Timeout task (used to trigger timeout,
 155    * cancel if we get the HELLO in time).
 156    */
 157   GNUNET_SCHEDULER_TaskIdentifier task;
 158
 159
 160 };
 161
 162
 163 /**
 164  * Opaque handle for a transmission-ready request.
 165  */
 166 struct GNUNET_TRANSPORT_TransmitHandle
 167 {
 168
 169   /**
 170    * We keep the transmit handles that are waiting for
 171    * a transport-level connection in a doubly linked list.
 172    */
 173   struct GNUNET_TRANSPORT_TransmitHandle *next;
 174
 175   /**
 176    * We keep the transmit handles that are waiting for
 177    * a transport-level connection in a doubly linked list.
 178    */
 179   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 180
 181   /**
 182    * Handle of the main transport data structure.
 183    */
 184   struct GNUNET_TRANSPORT_Handle *handle;
 185
 186   /**
 187    * Neighbour for this handle, can be NULL if the service
 188    * is not yet connected to the target.
 189    */
 190   struct NeighbourList *neighbour;
 191
 192   /**
 193    * Which peer is this transmission going to be for?  All
 194    * zeros if it is control-traffic to the service.
 195    */
 196   struct GNUNET_PeerIdentity target;
 197
 198   /**
 199    * Function to call when notify_size bytes are available
 200    * for transmission.
 201    */
 202   GNUNET_CONNECTION_TransmitReadyNotify notify;
 203
 204   /**
 205    * Closure for notify.
 206    */
 207   void *notify_cls;
 208
 209   /**
 210    * transmit_ready task Id.  The task is used to introduce the
 211    * artificial delay that may be required to maintain the bandwidth
 212    * limits.  Later, this will be the ID of the "transmit_timeout"
 213    * task which is used to signal a timeout if the transmission could
 214    * not be done in a timely fashion.
 215    */
 216   GNUNET_SCHEDULER_TaskIdentifier notify_delay_task;
 217
 218   /**
 219    * Timeout for this request.
 220    */
 221   struct GNUNET_TIME_Absolute timeout;
 222
 223   /**
 224    * How many bytes is our notify callback waiting for?
 225    */
 226   size_t notify_size;
 227
 228   /**
 229    * How important is this message?
 230    */
 231   unsigned int priority;
 232
 233 };
 234
 235
 236 /**
 237  * Handle for the transport service (includes all of the
 238  * state for the transport service).
 239  */
 240 struct GNUNET_TRANSPORT_Handle
 241 {
 242
 243   /**
 244    * Closure for the callbacks.
 245    */
 246   void *cls;
 247
 248   /**
 249    * Function to call for received data.
 250    */
 251   GNUNET_TRANSPORT_ReceiveCallback rec;
 252
 253   /**
 254    * function to call on connect events
 255    */
 256   GNUNET_TRANSPORT_NotifyConnect nc_cb;
 257
 258   /**
 259    * function to call on disconnect events
 260    */
 261   GNUNET_TRANSPORT_NotifyDisconnect nd_cb;
 262
 263   /**
 264    * The current HELLO message for this peer.  Updated
 265    * whenever transports change their addresses.
 266    */
 267   struct GNUNET_HELLO_Message *my_hello;
 268
 269   /**
 270    * My client connection to the transport service.
 271    */
 272   struct GNUNET_CLIENT_Connection *client;
 273
 274   /**
 275    * Handle to our registration with the client for notification.
 276    */
 277   struct GNUNET_CLIENT_TransmitHandle *network_handle;
 278
 279   /**
 280    * Linked list of transmit handles that are waiting for the
 281    * transport to connect to the respective peer.  When we
 282    * receive notification that the transport connected to a
 283    * peer, we go over this list and check if someone has already
 284    * requested a transmission to the new peer; if so, we trigger
 285    * the next step.
 286    */
 287   struct GNUNET_TRANSPORT_TransmitHandle *connect_wait_head;
 288
 289   /**
 290    * Linked list of transmit handles that are waiting for the
 291    * transport to be ready for transmission to the respective
 292    * peer.  When we
 293    * receive notification that the transport disconnected from
 294    * a peer, we go over this list and move the entry back to
 295    * the connect_wait list.
 296    */
 297   struct GNUNET_TRANSPORT_TransmitHandle *connect_ready_head;
 298
 299   /**
 300    * Linked list of pending requests for our HELLO.
 301    */
 302   struct HelloWaitList *hwl_head;
 303
 304   /**
 305    * My scheduler.
 306    */
 307   struct GNUNET_SCHEDULER_Handle *sched;
 308
 309   /**
 310    * My configuration.
 311    */
 312   const struct GNUNET_CONFIGURATION_Handle *cfg;
 313
 314   /**
 315    * Linked list of the current neighbours of this peer.
 316    */
 317   struct NeighbourList *neighbours;
 318
 319   /**
 320    * ID of the task trying to reconnect to the
 321    * service.
 322    */
 323   GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
 324
 325   /**
 326    * Delay until we try to reconnect.
 327    */
 328   struct GNUNET_TIME_Relative reconnect_delay;
 329
 330   /**
 331    * Do we currently have a transmission pending?
 332    * (schedule transmission was called but has not
 333    * yet succeeded)?
 334    */
 335   int transmission_scheduled;
 336 };
 337
 338
 339 static struct NeighbourList *
 340 find_neighbour (struct GNUNET_TRANSPORT_Handle *h,
 341                 const struct GNUNET_PeerIdentity *peer)
 342 {
 343   struct NeighbourList *pos;
 344
 345   pos = h->neighbours;
 346   while ((pos != NULL) &&
 347          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
 348     pos = pos->next;
 349   return pos;
 350 }
 351
 352
 353 /**
 354  * Schedule the task to send one message from the
 355  * connect_ready list to the service.
 356  */
 357 static void schedule_transmission (struct GNUNET_TRANSPORT_Handle *h);
 358
 359
 360 /**
 361  * Transmit message to client...
 362  */
 363 static size_t
 364 transport_notify_ready (void *cls, size_t size, void *buf)
 365 {
 366   struct GNUNET_TRANSPORT_Handle *h = cls;
 367   struct GNUNET_TRANSPORT_TransmitHandle *th;
 368   struct NeighbourList *n;
 369   size_t ret;
 370   char *cbuf;
 371
 372   h->network_handle = NULL;
 373   h->transmission_scheduled = GNUNET_NO;
 374   if (buf == NULL)
 375     {
 376 #if DEBUG_TRANSPORT
 377       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 378                   "Could not transmit to transport service, cancelling pending requests\n");
 379 #endif
 380       th = h->connect_ready_head;
 381       if (th->next != NULL)
 382         th->next->prev = NULL;
 383       h->connect_ready_head = th->next;
 384       if (NULL != (n = th->neighbour))
 385         {
 386           GNUNET_assert (n->transmit_handle == th);
 387           n->transmit_handle = NULL;
 388         }
 389       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 390         {
 391           GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 392           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 393         }
 394       if (NULL != th->notify)
 395         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
 396       GNUNET_free (th);
 397       if (h->connect_ready_head != NULL)
 398         schedule_transmission (h);      /* FIXME: is this ok? */
 399       return 0;
 400     }
 401 #if DEBUG_TRANSPORT
 402   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 403               "Ready to transmit %u bytes to transport service\n", size);
 404 #endif
 405   cbuf = buf;
 406   ret = 0;
 407   h->network_handle = NULL;
 408   h->transmission_scheduled = GNUNET_NO;
 409   while ((h->connect_ready_head != NULL) &&
 410          (h->connect_ready_head->notify_size <= size))
 411     {
 412       th = h->connect_ready_head;
 413       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 414         {
 415           GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 416           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 417         }
 418       GNUNET_assert (th->notify_size <= size);
 419       if (th->next != NULL)
 420         th->next->prev = NULL;
 421       h->connect_ready_head = th->next;
 422       if (NULL != (n = th->neighbour))
 423         {
 424           GNUNET_assert (n->transmit_handle == th);
 425           n->transmit_handle = NULL;
 426         }
 427       if (NULL != th->notify)
 428         ret += th->notify (th->notify_cls, size, &cbuf[ret]);
 429       GNUNET_free (th);
 430       if (n != NULL)
 431         n->last_sent += ret;
 432       size -= ret;
 433     }
 434   if (h->connect_ready_head != NULL)
 435     schedule_transmission (h);
 436 #if DEBUG_TRANSPORT
 437   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 438               "Transmitting %u bytes to transport service\n", ret);
 439 #endif
 440   return ret;
 441 }
 442
 443
 444 /**
 445  * Schedule the task to send one message from the
 446  * connect_ready list to the service.
 447  */
 448 static void
 449 schedule_transmission (struct GNUNET_TRANSPORT_Handle *h)
 450 {
 451   struct GNUNET_TRANSPORT_TransmitHandle *th;
 452
 453   GNUNET_assert (NULL == h->network_handle);
 454   if (h->client == NULL)
 455     {
 456       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 457                   "Could not yet schedule transmission: we are not yet connected to the transport service!\n");
 458       return;                   /* not yet connected */
 459     }
 460   th = h->connect_ready_head;
 461   if (th == NULL)
 462     return;                     /* no request pending */
 463   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 464     {
 465       /* remove existing time out task, will be integrated
 466          with transmit_ready notification! */
 467       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 468       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 469     }
 470   h->transmission_scheduled = GNUNET_YES;
 471   h->network_handle = GNUNET_CLIENT_notify_transmit_ready (h->client,
 472                                                            th->notify_size,
 473                                                            GNUNET_TIME_absolute_get_remaining
 474                                                            (th->timeout),
 475                                                            GNUNET_NO,
 476                                                            &transport_notify_ready,
 477                                                            h);
 478   GNUNET_assert (NULL != h->network_handle);
 479 }
 480
 481
 482 /**
 483  * Insert the given transmit handle in the given sorted
 484  * doubly linked list based on timeout.
 485  *
 486  * @param head pointer to the head of the linked list
 487  * @param th element to insert into the list
 488  */
 489 static void
 490 insert_transmit_handle (struct GNUNET_TRANSPORT_TransmitHandle **head,
 491                         struct GNUNET_TRANSPORT_TransmitHandle *th)
 492 {
 493   struct GNUNET_TRANSPORT_TransmitHandle *pos;
 494   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 495
 496   pos = *head;
 497   prev = NULL;
 498   while ((pos != NULL) && (pos->timeout.value < th->timeout.value))
 499     {
 500       prev = pos;
 501       pos = pos->next;
 502     }
 503   if (prev == NULL)
 504     {
 505       th->next = *head;
 506       if (th->next != NULL)
 507         th->next->prev = th;
 508       *head = th;
 509     }
 510   else
 511     {
 512       th->next = pos;
 513       th->prev = prev;
 514       prev->next = th;
 515       if (pos != NULL)
 516         pos->prev = th;
 517     }
 518 }
 519
 520
 521 /**
 522  * Cancel a pending notify delay task (if pending) and also remove the
 523  * given transmit handle from whatever list is on.
 524  *
 525  * @param th handle for the transmission request to manipulate
 526  */
 527 static void
 528 remove_from_any_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
 529 {
 530   struct GNUNET_TRANSPORT_Handle *h;
 531
 532   h = th->handle;
 533   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 534     {
 535       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 536       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 537     }
 538   if (th->prev == NULL)
 539     {
 540       if (th == h->connect_wait_head)
 541         h->connect_wait_head = th->next;
 542       else
 543         h->connect_ready_head = th->next;
 544     }
 545   else
 546     {
 547       th->prev->next = th->next;
 548     }
 549   if (th->next != NULL)
 550     th->next->prev = th->prev;
 551 }
 552
 553
 554 /**
 555  * Schedule a request to connect to the given
 556  * neighbour (and if successful, add the specified
 557  * handle to the wait list).
 558  *
 559  * @param th handle for a request to transmit once we
 560  *        have connected
 561  */
 562 static void try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th);
 563
 564
 565 /**
 566  * Called when our transmit request timed out before any transport
 567  * reported success connecting to the desired peer or before the
 568  * transport was ready to receive.  Signal error and free
 569  * TransmitHandle.
 570  */
 571 static void
 572 peer_transmit_timeout (void *cls,
 573                        const struct GNUNET_SCHEDULER_TaskContext *tc)
 574 {
 575   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 576
 577   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 578   if (th->neighbour != NULL)
 579     th->neighbour->transmit_handle = NULL;
 580 #if DEBUG_TRANSPORT
 581   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 582               "Request for transmission to peer `%s' timed out.\n",
 583               GNUNET_i2s (&th->target));
 584 #endif
 585   remove_from_any_list (th);
 586   if (NULL != th->notify)
 587     th->notify (th->notify_cls, 0, NULL);
 588   GNUNET_free (th);
 589 }
 590
 591
 592
 593
 594 /**
 595  * Queue control request for transmission to the transport
 596  * service.
 597  *
 598  * @param h handle to the transport service
 599  * @param size number of bytes to be transmitted
 600  * @param at_head request must be added to the head of the queue
 601  *        (otherwise request will be appended)
 602  * @param timeout how long this transmission can wait (at most)
 603  * @param notify function to call to get the content
 604  * @param notify_cls closure for notify
 605  */
 606 static void
 607 schedule_control_transmit (struct GNUNET_TRANSPORT_Handle *h,
 608                            size_t size,
 609                            int at_head,
 610                            struct GNUNET_TIME_Relative timeout,
 611                            GNUNET_CONNECTION_TransmitReadyNotify notify,
 612                            void *notify_cls)
 613 {
 614   struct GNUNET_TRANSPORT_TransmitHandle *th;
 615
 616 #if DEBUG_TRANSPORT
 617   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 618               "Control transmit of %u bytes within %llums requested\n",
 619               size, (unsigned long long) timeout.value);
 620 #endif
 621   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
 622   th->handle = h;
 623   th->notify = notify;
 624   th->notify_cls = notify_cls;
 625   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 626   th->notify_size = size;
 627   th->notify_delay_task
 628     = GNUNET_SCHEDULER_add_delayed (h->sched,
 629                                     timeout, &peer_transmit_timeout, th);
 630   if (at_head)
 631     {
 632       th->next = h->connect_ready_head;
 633       h->connect_ready_head = th;
 634       if (th->next != NULL)
 635         th->next->prev = th;
 636     }
 637   else
 638     {
 639       insert_transmit_handle (&h->connect_ready_head, th);
 640     }
 641   if (GNUNET_NO == h->transmission_scheduled)
 642     schedule_transmission (h);
 643 }
 644
 645
 646 /**
 647  * Update the quota values for the given neighbour now.
 648  */
 649 static void
 650 update_quota (struct NeighbourList *n)
 651 {
 652   struct GNUNET_TIME_Relative delta;
 653   uint64_t allowed;
 654   uint64_t remaining;
 655
 656   delta = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
 657   allowed = delta.value * n->quota_out;
 658   if (n->last_sent < allowed)
 659     {
 660       remaining = allowed - n->last_sent;
 661       if (n->quota_out > 0)
 662         remaining /= n->quota_out;
 663       else
 664         remaining = 0;
 665       if (remaining > MAX_BANDWIDTH_CARRY)
 666         remaining = MAX_BANDWIDTH_CARRY;
 667       n->last_sent = 0;
 668       n->last_quota_update = GNUNET_TIME_absolute_get ();
 669       n->last_quota_update.value -= remaining;
 670     }
 671   else
 672     {
 673       n->last_sent -= allowed;
 674       n->last_quota_update = GNUNET_TIME_absolute_get ();
 675     }
 676 }
 677
 678
 679 struct SetQuotaContext
 680 {
 681   struct GNUNET_TRANSPORT_Handle *handle;
 682
 683   struct GNUNET_PeerIdentity target;
 684
 685   GNUNET_SCHEDULER_Task cont;
 686
 687   void *cont_cls;
 688
 689   struct GNUNET_TIME_Absolute timeout;
 690
 691   uint32_t quota_in;
 692 };
 693
 694
 695 static size_t
 696 send_set_quota (void *cls, size_t size, void *buf)
 697 {
 698   struct SetQuotaContext *sqc = cls;
 699   struct QuotaSetMessage *msg;
 700
 701   if (buf == NULL)
 702     {
 703       GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 704                                          sqc->cont,
 705                                          sqc->cont_cls,
 706                                          GNUNET_SCHEDULER_REASON_TIMEOUT);
 707       GNUNET_free (sqc);
 708       return 0;
 709     }
 710 #if DEBUG_TRANSPORT
 711   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 712               "Transmitting `%s' request with respect to `%4s'.\n",
 713               "SET_QUOTA", GNUNET_i2s (&sqc->target));
 714 #endif
 715   GNUNET_assert (size >= sizeof (struct QuotaSetMessage));
 716   msg = buf;
 717   msg->header.size = htons (sizeof (struct QuotaSetMessage));
 718   msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
 719   msg->quota_in = htonl (sqc->quota_in);
 720   memcpy (&msg->peer, &sqc->target, sizeof (struct GNUNET_PeerIdentity));
 721   if (sqc->cont != NULL)
 722     GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 723                                        sqc->cont,
 724                                        sqc->cont_cls,
 725                                        GNUNET_SCHEDULER_REASON_PREREQ_DONE);
 726   GNUNET_free (sqc);
 727   return sizeof (struct QuotaSetMessage);
 728 }
 729
 730
 731 /**
 732  * Set the share of incoming bandwidth for the given
 733  * peer to the specified amount.
 734  *
 735  * @param handle connection to transport service
 736  * @param target who's bandwidth quota is being changed
 737  * @param quota_in incoming bandwidth quota in bytes per ms
 738  * @param quota_out outgoing bandwidth quota in bytes per ms
 739  * @param timeout how long to wait until signaling failure if
 740  *        we can not communicate the quota change
 741  * @param cont continuation to call when done, will be called
 742  *        either with reason "TIMEOUT" or with reason "PREREQ_DONE"
 743  * @param cont_cls closure for continuation
 744  */
 745 void
 746 GNUNET_TRANSPORT_set_quota (struct GNUNET_TRANSPORT_Handle *handle,
 747                             const struct GNUNET_PeerIdentity *target,
 748                             uint32_t quota_in,
 749                             uint32_t quota_out,
 750                             struct GNUNET_TIME_Relative timeout,
 751                             GNUNET_SCHEDULER_Task cont, void *cont_cls)
 752 {
 753   struct NeighbourList *n;
 754   struct SetQuotaContext *sqc;
 755
 756   n = find_neighbour (handle, target);
 757   if (n != NULL)
 758     {
 759       update_quota (n);
 760       if (n->quota_out < quota_out)
 761         n->last_quota_update = GNUNET_TIME_absolute_get ();
 762       n->quota_out = quota_out;
 763     }
 764   sqc = GNUNET_malloc (sizeof (struct SetQuotaContext));
 765   sqc->handle = handle;
 766   sqc->target = *target;
 767   sqc->cont = cont;
 768   sqc->cont_cls = cont_cls;
 769   sqc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 770   sqc->quota_in = quota_in;
 771   schedule_control_transmit (handle,
 772                              sizeof (struct QuotaSetMessage),
 773                              GNUNET_NO, timeout, &send_set_quota, sqc);
 774 }
 775
 776
 777 /**
 778  * A "get_hello" request has timed out.  Signal the client
 779  * and clean up.
 780  */
 781 static void
 782 hello_wait_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 783 {
 784   struct HelloWaitList *hwl = cls;
 785   struct HelloWaitList *pos;
 786   struct HelloWaitList *prev;
 787
 788   hwl->task = GNUNET_SCHEDULER_NO_TASK;
 789   if (GNUNET_TIME_absolute_get_remaining (hwl->timeout).value > 0)
 790     {
 791 #if DEBUG_TRANSPORT
 792       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 793                   _
 794                   ("First attempt to obtain `%s' from transport service failed, will try again for %llums.\n"),
 795                   "HELLO",
 796                   GNUNET_TIME_absolute_get_remaining (hwl->timeout).value);
 797 #endif
 798       hwl->task = GNUNET_SCHEDULER_add_delayed (hwl->handle->sched,
 799                                                 GNUNET_TIME_absolute_get_remaining
 800                                                 (hwl->timeout),
 801                                                 &hello_wait_timeout, hwl);
 802       return;
 803     }
 804   /* signal timeout */
 805   GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 806               _("Timeout trying to obtain `%s' from transport service.\n"),
 807               "HELLO");
 808   prev = NULL;
 809   pos = hwl->handle->hwl_head;
 810   while (pos != hwl)
 811     {
 812       GNUNET_assert (pos != NULL);
 813       prev = pos;
 814       pos = pos->next;
 815     }
 816   if (prev == NULL)
 817     hwl->handle->hwl_head = hwl->next;
 818   else
 819     prev->next = hwl->next;
 820   if (hwl->rec != NULL)
 821     hwl->rec (hwl->rec_cls, NULL);
 822   GNUNET_free (hwl);
 823 }
 824
 825
 826 /**
 827  * Obtain the HELLO message for this peer.
 828  *
 829  * @param handle connection to transport service
 830  * @param timeout how long to wait for the HELLO
 831  * @param rec function to call with the HELLO, sender will be our peer
 832  *            identity; message and sender will be NULL on timeout
 833  *            (handshake with transport service pending/failed).
 834  *             cost estimate will be 0.
 835  * @param rec_cls closure for rec
 836  */
 837 void
 838 GNUNET_TRANSPORT_get_hello (struct GNUNET_TRANSPORT_Handle *handle,
 839                             GNUNET_TRANSPORT_HelloUpdateCallback rec,
 840                             void *rec_cls)
 841 {
 842   struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pk;
 843   struct GNUNET_PeerIdentity me;
 844   struct HelloWaitList *hwl;
 845
 846   if (handle->my_hello == NULL)
 847     {
 848       hwl = GNUNET_malloc (sizeof (struct HelloWaitList));
 849       hwl->next = handle->hwl_head;
 850       handle->hwl_head = hwl;
 851       hwl->handle = handle;
 852       hwl->rec = rec;
 853       hwl->rec_cls = rec_cls;
 854       /* hwl->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 855        * Timeout not needed, because we should notify on change.
 856        * FIXME: set up scheduler to notify on modification?
 857
 858       hwl->task = GNUNET_SCHEDULER_add_delayed (handle->sched,
 859                                                 timeout,
 860                                                 &hello_wait_timeout, hwl);
 861       */
 862       return;
 863     }
 864   GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_key (handle->my_hello, &pk));
 865   GNUNET_CRYPTO_hash (&pk,
 866                       sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 867                       &me.hashPubKey);
 868
 869   rec (rec_cls, (const struct GNUNET_MessageHeader *) handle->my_hello);
 870 }
 871
 872
 873 static size_t
 874 send_hello (void *cls, size_t size, void *buf)
 875 {
 876   struct GNUNET_MessageHeader *hello = cls;
 877   uint16_t msize;
 878
 879   if (buf == NULL)
 880     {
 881 #if DEBUG_TRANSPORT
 882       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 883                   "Timeout while trying to transmit `%s' request.\n",
 884                   "HELLO");
 885 #endif
 886       GNUNET_free (hello);
 887       return 0;
 888     }
 889 #if DEBUG_TRANSPORT
 890   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 891               "Transmitting `%s' request.\n", "HELLO");
 892 #endif
 893   msize = ntohs (hello->size);
 894   GNUNET_assert (size >= msize);
 895   memcpy (buf, hello, msize);
 896   GNUNET_free (hello);
 897   return msize;
 898 }
 899
 900
 901 /**
 902  * Offer the transport service the HELLO of another peer.  Note that
 903  * the transport service may just ignore this message if the HELLO is
 904  * malformed or useless due to our local configuration.
 905  *
 906  * @param handle connection to transport service
 907  * @param hello the hello message
 908  */
 909 void
 910 GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle,
 911                               const struct GNUNET_MessageHeader *hello)
 912 {
 913   struct GNUNET_MessageHeader *hc;
 914   uint16_t size;
 915
 916   if (handle->client == NULL)
 917     {
 918 #if DEBUG_TRANSPORT
 919       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 920                   "Not connected to transport service, dropping offered HELLO\n");
 921 #endif
 922       return;
 923     }
 924   GNUNET_break (ntohs (hello->type) == GNUNET_MESSAGE_TYPE_HELLO);
 925   size = ntohs (hello->size);
 926   GNUNET_break (size >= sizeof (struct GNUNET_MessageHeader));
 927   hc = GNUNET_malloc (size);
 928   memcpy (hc, hello, size);
 929   schedule_control_transmit (handle,
 930                              size,
 931                              GNUNET_NO, OFFER_HELLO_TIMEOUT, &send_hello, hc);
 932 }
 933
 934
 935 /**
 936  * Function we use for handling incoming messages.
 937  */
 938 static void demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg);
 939
 940
 941 static size_t
 942 send_start (void *cls, size_t size, void *buf)
 943 {
 944   struct GNUNET_MessageHeader *s = buf;
 945
 946   if (buf == NULL)
 947     {
 948 #if DEBUG_TRANSPORT
 949       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 950                   "Timeout while trying to transmit `%s' request.\n",
 951                   "START");
 952 #endif
 953       return 0;
 954     }
 955 #if DEBUG_TRANSPORT
 956   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 957               "Transmitting `%s' request.\n", "START");
 958 #endif
 959   GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
 960   s->size = htons (sizeof (struct GNUNET_MessageHeader));
 961   s->type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_START);
 962   return sizeof (struct GNUNET_MessageHeader);
 963 }
 964
 965
 966 /**
 967  * We're ready to transmit the request that the transport service
 968  * should connect to a new peer.  In addition to sending the
 969  * request, schedule the next phase for the transmission processing
 970  * that caused the connect request in the first place.
 971  */
 972 static size_t
 973 request_connect (void *cls, size_t size, void *buf)
 974 {
 975   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 976   struct TryConnectMessage *tcm;
 977   struct GNUNET_TRANSPORT_Handle *h;
 978
 979   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
 980   h = th->handle;
 981   if (buf == NULL)
 982     {
 983 #if DEBUG_TRANSPORT
 984       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 985                   "Failed to transmit `%s' request for `%4s' to service.\n",
 986                   "TRY_CONNECT", GNUNET_i2s (&th->target));
 987 #endif
 988       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
 989         {
 990           GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 991           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
 992         }
 993       if (NULL != th->notify)
 994         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
 995       GNUNET_free (th);
 996       return 0;
 997     }
 998 #if DEBUG_TRANSPORT
 999   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1000               "Transmitting `%s' message for `%4s' (need connection in %llu ms).\n",
1001               "TRY_CONNECT", GNUNET_i2s (&th->target),
1002               GNUNET_TIME_absolute_get_remaining (th->timeout).value);
1003 #endif
1004   GNUNET_assert (size >= sizeof (struct TryConnectMessage));
1005   tcm = buf;
1006   tcm->header.size = htons (sizeof (struct TryConnectMessage));
1007   tcm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TRY_CONNECT);
1008   tcm->reserved = htonl (0);
1009   memcpy (&tcm->peer, &th->target, sizeof (struct GNUNET_PeerIdentity));
1010   th->notify_delay_task
1011     = GNUNET_SCHEDULER_add_delayed (h->sched,
1012                                     GNUNET_TIME_absolute_get_remaining
1013                                     (th->timeout),
1014                                     &peer_transmit_timeout, th);
1015   insert_transmit_handle (&h->connect_wait_head, th);
1016   return sizeof (struct TryConnectMessage);
1017 }
1018
1019
1020 /**
1021  * Schedule a request to connect to the given
1022  * neighbour (and if successful, add the specified
1023  * handle to the wait list).
1024  *
1025  * @param th handle for a request to transmit once we
1026  *        have connected
1027  */
1028 static void
1029 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th)
1030 {
1031   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1032   schedule_control_transmit (th->handle,
1033                              sizeof (struct TryConnectMessage),
1034                              GNUNET_NO,
1035                              GNUNET_TIME_absolute_get_remaining (th->timeout),
1036                              &request_connect, th);
1037 }
1038
1039
1040 /**
1041  * Task for delayed attempts to reconnect to a peer.
1042  *
1043  * @param cls must be a transmit handle that determines the peer
1044  *        to which we will try to connect
1045  * @param tc scheduler information about why we were triggered (not used)
1046  */
1047 static void
1048 try_connect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1049 {
1050   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1051
1052   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1053   try_connect (th);
1054 }
1055
1056
1057 /**
1058  * Remove neighbour from our list.  Will automatically
1059  * trigger a re-connect attempt if we have messages pending
1060  * for this peer.
1061  *
1062  * @param h our state
1063  * @param peer the peer to remove
1064  */
1065 static void
1066 remove_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1067                   const struct GNUNET_PeerIdentity *peer)
1068 {
1069   struct NeighbourList *prev;
1070   struct NeighbourList *pos;
1071   struct GNUNET_TRANSPORT_TransmitHandle *th;
1072
1073 #if DEBUG_TRANSPORT
1074   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1075               "Removing neighbour `%s' from list of connected peers.\n",
1076               GNUNET_i2s (peer));
1077 #endif
1078   prev = NULL;
1079   pos = h->neighbours;
1080   while ((pos != NULL) &&
1081          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
1082     {
1083       prev = pos;
1084       pos = pos->next;
1085     }
1086   if (pos == NULL)
1087     {
1088       GNUNET_break (0);
1089       return;
1090     }
1091   if (prev == NULL)
1092     h->neighbours = pos->next;
1093   else
1094     prev->next = pos->next;
1095   if (NULL != (th = pos->transmit_handle))
1096     {
1097       pos->transmit_handle = NULL;
1098       th->neighbour = NULL;
1099       remove_from_any_list (th);
1100       if (GNUNET_TIME_absolute_get_remaining (th->timeout).value <=
1101           CONNECT_RETRY_TIMEOUT.value)
1102         {
1103           /* signal error */
1104           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1105                       _
1106                       ("Connection with `%4s' failed and timeout was in the past, giving up on message delivery.\n"),
1107                       GNUNET_i2s (peer));
1108           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1109           peer_transmit_timeout (th, NULL);
1110         }
1111       else
1112         {
1113           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1114                       _
1115                       ("Connection with `%4s' failed, will keep trying for %llu ms to deliver message\n"),
1116                       GNUNET_i2s (peer),
1117                       GNUNET_TIME_absolute_get_remaining (th->timeout).value);
1118           /* try again in a bit */
1119           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1120           th->notify_delay_task
1121             = GNUNET_SCHEDULER_add_delayed (h->sched,
1122                                             CONNECT_RETRY_TIMEOUT,
1123                                             &try_connect_task, th);
1124         }
1125     }
1126   if (h->nc_cb != NULL)
1127     h->nd_cb (h->cls, peer);
1128   GNUNET_free (pos);
1129 }
1130
1131
1132 /**
1133  * Try again to connect to transport service.
1134  */
1135 static void
1136 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1137 {
1138   struct GNUNET_TRANSPORT_Handle *h = cls;
1139   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1140   struct NeighbourList *n;
1141
1142   /* Forget about all neighbours that we used to be connected
1143      to */
1144   while (NULL != (n = h->neighbours))
1145     remove_neighbour (h, &n->id);
1146 #if DEBUG_TRANSPORT
1147   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service.\n");
1148 #endif
1149   GNUNET_assert (h->client == NULL);
1150   h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1151   h->client = GNUNET_CLIENT_connect (h->sched, "transport", h->cfg);
1152   GNUNET_assert (h->client != NULL);
1153   /* make sure we don't send "START" twice,
1154      remove existing entry from queue (if present) */
1155   pos = h->connect_ready_head;
1156   while (pos != NULL)
1157     {
1158       if (pos->notify == &send_start)
1159         {
1160           if (pos->prev == NULL)
1161             h->connect_ready_head = pos->next;
1162           else
1163             pos->prev->next = pos->next;
1164           if (pos->next != NULL)
1165             pos->next->prev = pos->prev;
1166           GNUNET_assert (pos->neighbour == NULL);
1167           if (GNUNET_SCHEDULER_NO_TASK != pos->notify_delay_task)
1168             {
1169               GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1170               pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1171             }
1172           GNUNET_free (pos);
1173           break;
1174         }
1175       pos = pos->next;
1176     }
1177   schedule_control_transmit (h,
1178                              sizeof (struct GNUNET_MessageHeader),
1179                              GNUNET_YES,
1180                              GNUNET_TIME_UNIT_FOREVER_REL, &send_start, NULL);
1181   GNUNET_CLIENT_receive (h->client,
1182                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1183 }
1184
1185
1186 /**
1187  * Function that will schedule the job that will try
1188  * to connect us again to the client.
1189  */
1190 static void
1191 schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h)
1192 {
1193 #if DEBUG_TRANSPORT
1194   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1195               "Scheduling task to reconnect to transport service in %llu ms.\n",
1196               h->reconnect_delay.value);
1197 #endif
1198   GNUNET_assert (h->client == NULL);
1199   GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
1200   h->reconnect_task
1201     = GNUNET_SCHEDULER_add_delayed (h->sched,
1202                                     h->reconnect_delay, &reconnect, h);
1203   h->reconnect_delay = GNUNET_TIME_UNIT_SECONDS;
1204 }
1205
1206
1207 /**
1208  * We are connected to the respective peer, check the
1209  * bandwidth limits and schedule the transmission.
1210  */
1211 static void schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th);
1212
1213
1214 /**
1215  * Function called by the scheduler when the timeout
1216  * for bandwidth availablility for the target
1217  * neighbour is reached.
1218  */
1219 static void
1220 transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1221 {
1222   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1223
1224   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1225   schedule_request (th);
1226 }
1227
1228
1229 /**
1230  * Remove the given transmit handle from the wait list.  Does NOT free
1231  * it.
1232  */
1233 static void
1234 remove_from_wait_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
1235 {
1236   if (th->prev == NULL)
1237     th->handle->connect_wait_head = th->next;
1238   else
1239     th->prev->next = th->next;
1240   if (th->next != NULL)
1241     th->next->prev = th->prev;
1242 }
1243
1244
1245 /**
1246  * We are connected to the respective peer, check the
1247  * bandwidth limits and schedule the transmission.
1248  */
1249 static void
1250 schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th)
1251 {
1252   struct GNUNET_TRANSPORT_Handle *h;
1253   struct GNUNET_TIME_Relative duration;
1254   struct NeighbourList *n;
1255   uint64_t available;
1256
1257   h = th->handle;
1258   n = th->neighbour;
1259   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1260     {
1261       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
1262       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1263     }
1264   /* check outgoing quota */
1265   duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1266   if (duration.value > MIN_QUOTA_REFRESH_TIME)
1267     {
1268       update_quota (n);
1269       duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1270     }
1271   available = duration.value * n->quota_out;
1272   if (available < n->last_sent + th->notify_size)
1273     {
1274       /* calculate how much bandwidth we'd still need to
1275          accumulate and based on that how long we'll have
1276          to wait... */
1277       available = n->last_sent + th->notify_size - available;
1278       duration = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
1279                                                 available / n->quota_out);
1280       if (th->timeout.value <
1281           GNUNET_TIME_relative_to_absolute (duration).value)
1282         {
1283           /* signal timeout! */
1284 #if DEBUG_TRANSPORT
1285           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1286                       "Would need %llu ms before bandwidth is available for delivery to `%4s', that is too long.  Signaling timeout.\n",
1287                       duration.value, GNUNET_i2s (&th->target));
1288 #endif
1289           remove_from_wait_list (th);
1290           if (NULL != th->notify)
1291             GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1292           GNUNET_free (th);
1293           return;
1294         }
1295 #if DEBUG_TRANSPORT
1296       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1297                   "Need more bandwidth, delaying delivery to `%4s' by %llu ms\n",
1298                   GNUNET_i2s (&th->target), duration.value);
1299 #endif
1300       th->notify_delay_task
1301         = GNUNET_SCHEDULER_add_delayed (h->sched,
1302                                         duration, &transmit_ready, th);
1303       return;
1304     }
1305 #if DEBUG_TRANSPORT
1306   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1307               "Bandwidth available for transmission to `%4s'\n",
1308               GNUNET_i2s (&n->id));
1309 #endif
1310   if (GNUNET_NO == n->transmit_ok)
1311     {
1312       /* we may be ready, but transport service is not;
1313          wait for SendOkMessage or timeout */
1314 #if DEBUG_TRANSPORT
1315       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1316                   "Need to wait for transport service `%s' message\n",
1317                   "SEND_OK");
1318 #endif
1319       th->notify_delay_task
1320         = GNUNET_SCHEDULER_add_delayed (h->sched,
1321                                         GNUNET_TIME_absolute_get_remaining
1322                                         (th->timeout), &peer_transmit_timeout,
1323                                         th);
1324       return;
1325     }
1326   n->transmit_ok = GNUNET_NO;
1327   remove_from_wait_list (th);
1328 #if DEBUG_TRANSPORT
1329   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1330               "Moving message for `%4s' to ready list\n",
1331               GNUNET_i2s (&n->id));
1332 #endif
1333   insert_transmit_handle (&h->connect_ready_head, th);
1334   if (GNUNET_NO == h->transmission_scheduled)
1335     schedule_transmission (h);
1336 }
1337
1338
1339 /**
1340  * Add neighbour to our list
1341  */
1342 static void
1343 add_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1344                uint32_t quota_out,
1345                struct GNUNET_TIME_Relative latency,
1346                uint16_t distance,
1347                const struct GNUNET_PeerIdentity *pid)
1348 {
1349   struct NeighbourList *n;
1350   struct GNUNET_TRANSPORT_TransmitHandle *prev;
1351   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1352   struct GNUNET_TRANSPORT_TransmitHandle *next;
1353
1354   /* check for duplicates */
1355   if (NULL != find_neighbour (h, pid))
1356     {
1357       GNUNET_break (0);
1358       return;
1359     }
1360 #if DEBUG_TRANSPORT
1361   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1362               "Creating entry for new neighbour `%4s'.\n", GNUNET_i2s (pid));
1363 #endif
1364   n = GNUNET_malloc (sizeof (struct NeighbourList));
1365   n->id = *pid;
1366   n->last_quota_update = GNUNET_TIME_absolute_get ();
1367   n->quota_out = quota_out;
1368   n->next = h->neighbours;
1369   n->transmit_ok = GNUNET_YES;
1370   h->neighbours = n;
1371   if (h->nc_cb != NULL)
1372     h->nc_cb (h->cls, &n->id, latency, distance);
1373   prev = NULL;
1374   pos = h->connect_wait_head;
1375   while (pos != NULL)
1376     {
1377       next = pos->next;
1378       if (0 == memcmp (pid,
1379                        &pos->target, sizeof (struct GNUNET_PeerIdentity)))
1380         {
1381           pos->neighbour = n;
1382           GNUNET_assert (NULL == n->transmit_handle);
1383           n->transmit_handle = pos;
1384           if (prev == NULL)
1385             h->connect_wait_head = next;
1386           else
1387             prev->next = next;
1388           if (GNUNET_YES == n->received_ack)
1389             {
1390 #if DEBUG_TRANSPORT
1391               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1392                           "Found pending request for `%4s' will trigger it now.\n",
1393                           GNUNET_i2s (&pos->target));
1394 #endif
1395               if (pos->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1396                 {
1397                   GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1398                   pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1399                 }
1400               schedule_request (pos);
1401             }
1402           else
1403             {
1404 #if DEBUG_TRANSPORT
1405               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1406                           "Found pending request for `%4s' but still need `%s' before proceeding.\n",
1407                           GNUNET_i2s (&pos->target), "ACK");
1408 #endif
1409             }
1410           break;
1411         }
1412       prev = pos;
1413       pos = next;
1414     }
1415 }
1416
1417
1418 /**
1419  * Connect to the transport service.  Note that the connection may
1420  * complete (or fail) asynchronously.
1421  *
1422
1423  * @param sched scheduler to use
1424  * @param cfg configuration to use
1425  * @param cls closure for the callbacks
1426  * @param rec receive function to call
1427  * @param nc function to call on connect events
1428  * @param nd function to call on disconnect events
1429  */
1430 struct GNUNET_TRANSPORT_Handle *
1431 GNUNET_TRANSPORT_connect (struct GNUNET_SCHEDULER_Handle *sched,
1432                           const struct GNUNET_CONFIGURATION_Handle *cfg,
1433                           void *cls,
1434                           GNUNET_TRANSPORT_ReceiveCallback rec,
1435                           GNUNET_TRANSPORT_NotifyConnect nc,
1436                           GNUNET_TRANSPORT_NotifyDisconnect nd)
1437 {
1438   struct GNUNET_TRANSPORT_Handle *ret;
1439
1440   GNUNET_ARM_start_services (cfg, sched, "peerinfo", "transport", NULL);
1441   ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_Handle));
1442   ret->sched = sched;
1443   ret->cfg = cfg;
1444   ret->cls = cls;
1445   ret->rec = rec;
1446   ret->nc_cb = nc;
1447   ret->nd_cb = nd;
1448   ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
1449   schedule_reconnect (ret);
1450   return ret;
1451 }
1452
1453
1454 /**
1455  * Disconnect from the transport service.
1456  */
1457 void
1458 GNUNET_TRANSPORT_disconnect (struct GNUNET_TRANSPORT_Handle *handle)
1459 {
1460   struct GNUNET_TRANSPORT_TransmitHandle *th;
1461   struct NeighbourList *n;
1462   struct HelloWaitList *hwl;
1463   struct GNUNET_CLIENT_Connection *client;
1464
1465 #if DEBUG_TRANSPORT
1466   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transport disconnect called!\n");
1467 #endif
1468   while (NULL != (th = handle->connect_ready_head))
1469     {
1470       handle->connect_ready_head = th->next;
1471       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1472         {
1473           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1474           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1475         }
1476       if (NULL != th->notify)
1477         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1478       GNUNET_free (th);
1479     }
1480   while (NULL != (th = handle->connect_wait_head))
1481     {
1482       handle->connect_wait_head = th->next;
1483       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1484         {
1485           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1486           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1487         }
1488       if (NULL != th->notify)
1489         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1490       GNUNET_free (th);
1491     }
1492   while (NULL != (n = handle->neighbours))
1493     {
1494       handle->neighbours = n->next;
1495       if (NULL != (th = n->transmit_handle))
1496         {
1497           if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1498             {
1499               GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1500               th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1501             }
1502           if (NULL != th->notify)
1503             GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1504           GNUNET_free (th);
1505         }
1506       GNUNET_free (n);
1507     }
1508   while (NULL != (hwl = handle->hwl_head))
1509     {
1510       handle->hwl_head = hwl->next;
1511       GNUNET_SCHEDULER_cancel (handle->sched, hwl->task);
1512       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1513                   _
1514                   ("Disconnect while trying to obtain `%s' from transport service.\n"),
1515                   "HELLO");
1516       if (hwl->rec != NULL)
1517         hwl->rec (hwl->rec_cls, NULL);
1518       GNUNET_free (hwl);
1519     }
1520   if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
1521     {
1522       GNUNET_SCHEDULER_cancel (handle->sched, handle->reconnect_task);
1523       handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1524     }
1525   GNUNET_free_non_null (handle->my_hello);
1526   handle->my_hello = NULL;
1527   GNUNET_ARM_stop_services (handle->cfg, handle->sched, "transport",
1528                             "peerinfo", NULL);
1529   if (NULL != handle->network_handle)
1530     {
1531       GNUNET_CLIENT_notify_transmit_ready_cancel (handle->network_handle);
1532       handle->network_handle = NULL;
1533     }
1534   if (NULL != (client = handle->client))
1535     {
1536 #if DEBUG_TRANSPORT
1537       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1538                   "Disconnecting from transport service for good.\n");
1539 #endif
1540       handle->client = NULL;
1541       GNUNET_CLIENT_disconnect (client);
1542     }
1543   GNUNET_free (handle);
1544 }
1545
1546
1547 /**
1548  * Type of a function to call when we receive a message
1549  * from the service.
1550  *
1551  * @param cls closure
1552  * @param msg message received, NULL on timeout or fatal error
1553  */
1554 static void
1555 demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg)
1556 {
1557   struct GNUNET_TRANSPORT_Handle *h = cls;
1558   const struct DisconnectInfoMessage *dim;
1559   const struct ConnectInfoMessage *cim;
1560   const struct InboundMessage *im;
1561   const struct GNUNET_MessageHeader *imm;
1562   const struct SendOkMessage *okm;
1563   struct HelloWaitList *hwl;
1564   struct NeighbourList *n;
1565   struct GNUNET_PeerIdentity me;
1566   struct GNUNET_TRANSPORT_TransmitHandle *th;
1567   uint16_t size;
1568
1569   if ((msg == NULL) || (h->client == NULL))
1570     {
1571       if (h->client != NULL)
1572         {
1573 #if DEBUG_TRANSPORT
1574           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1575                       "Error receiving from transport service, disconnecting temporarily.\n");
1576 #endif
1577           if (h->network_handle != NULL)
1578             {
1579               GNUNET_CLIENT_notify_transmit_ready_cancel (h->network_handle);
1580               h->network_handle = NULL;
1581               h->transmission_scheduled = GNUNET_NO;
1582               th = h->connect_ready_head;
1583               /* add timeout again, we cancelled the transmit_ready task! */
1584               GNUNET_assert (th->notify_delay_task ==
1585                              GNUNET_SCHEDULER_NO_TASK);
1586               th->notify_delay_task =
1587                 GNUNET_SCHEDULER_add_delayed (h->sched,
1588                                               GNUNET_TIME_absolute_get_remaining
1589                                               (th->timeout),
1590                                               &peer_transmit_timeout, th);
1591             }
1592           GNUNET_CLIENT_disconnect (h->client);
1593           h->client = NULL;
1594           schedule_reconnect (h);
1595         }
1596       else
1597         {
1598           /* shutdown initiated from 'GNUNET_TRANSPORT_disconnect',
1599              finish clean up work! */
1600           GNUNET_free (h);
1601         }
1602       return;
1603     }
1604   GNUNET_CLIENT_receive (h->client,
1605                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1606   size = ntohs (msg->size);
1607   switch (ntohs (msg->type))
1608     {
1609     case GNUNET_MESSAGE_TYPE_HELLO:
1610       if (GNUNET_OK !=
1611           GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) msg,
1612                                &me))
1613         {
1614           GNUNET_break (0);
1615           break;
1616         }
1617 #if DEBUG_TRANSPORT
1618       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1619                   "Receiving (my own) `%s' message, I am `%4s'.\n",
1620                   "HELLO", GNUNET_i2s (&me));
1621 #endif
1622       GNUNET_free_non_null (h->my_hello);
1623       h->my_hello = NULL;
1624       if (size < sizeof (struct GNUNET_MessageHeader))
1625         {
1626           GNUNET_break (0);
1627           break;
1628         }
1629       h->my_hello = GNUNET_malloc (size);
1630       memcpy (h->my_hello, msg, size);
1631       while (NULL != (hwl = h->hwl_head))
1632         {
1633           h->hwl_head = hwl->next;
1634           GNUNET_SCHEDULER_cancel (h->sched, hwl->task);
1635           GNUNET_TRANSPORT_get_hello (h,
1636                                       hwl->rec, hwl->rec_cls);
1637           GNUNET_free (hwl);
1638         }
1639       break;
1640     case GNUNET_MESSAGE_TYPE_TRANSPORT_CONNECT:
1641       if (size != sizeof (struct ConnectInfoMessage))
1642         {
1643           GNUNET_break (0);
1644           break;
1645         }
1646       cim = (const struct ConnectInfoMessage *) msg;
1647 #if DEBUG_TRANSPORT
1648       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1649                   "Receiving `%s' message for `%4s'.\n",
1650                   "CONNECT", GNUNET_i2s (&cim->id));
1651 #endif
1652       add_neighbour (h,
1653                      ntohl (cim->quota_out),
1654                      GNUNET_TIME_relative_ntoh (cim->latency), ntohs(cim->distance), &cim->id);
1655       break;
1656     case GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT:
1657       if (size != sizeof (struct DisconnectInfoMessage))
1658         {
1659           GNUNET_break (0);
1660           break;
1661         }
1662       dim = (const struct DisconnectInfoMessage *) msg;
1663 #if DEBUG_TRANSPORT
1664       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1665                   "Receiving `%s' message for `%4s'.\n",
1666                   "DISCONNECT", GNUNET_i2s (&dim->peer));
1667 #endif
1668       remove_neighbour (h, &dim->peer);
1669       break;
1670     case GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_OK:
1671       if (size != sizeof (struct SendOkMessage))
1672         {
1673           GNUNET_break (0);
1674           break;
1675         }
1676       okm = (const struct SendOkMessage *) msg;
1677 #if DEBUG_TRANSPORT
1678       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1679                   "Receiving `%s' message, transmission %s.\n", "SEND_OK",
1680                   ntohl (okm->success) == GNUNET_OK ? "succeeded" : "failed");
1681 #endif
1682       n = find_neighbour (h, &okm->peer);
1683       GNUNET_assert (n != NULL);
1684       n->transmit_ok = GNUNET_YES;
1685       if (n->transmit_handle != NULL)
1686         {
1687 #if DEBUG_TRANSPORT
1688           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1689                       "Processing pending message for `%4s'\n",
1690                       GNUNET_i2s (&n->id));
1691 #endif
1692           GNUNET_SCHEDULER_cancel (h->sched,
1693                                    n->transmit_handle->notify_delay_task);
1694           n->transmit_handle->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1695           GNUNET_assert (GNUNET_YES == n->received_ack);
1696           schedule_request (n->transmit_handle);
1697         }
1698       break;
1699     case GNUNET_MESSAGE_TYPE_TRANSPORT_RECV:
1700 #if DEBUG_TRANSPORT
1701       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1702                   "Receiving `%s' message.\n", "RECV");
1703 #endif
1704       if (size <
1705           sizeof (struct InboundMessage) +
1706           sizeof (struct GNUNET_MessageHeader))
1707         {
1708           GNUNET_break (0);
1709           break;
1710         }
1711       im = (const struct InboundMessage *) msg;
1712       imm = (const struct GNUNET_MessageHeader *) &im[1];
1713       if (ntohs (imm->size) + sizeof (struct InboundMessage) != size)
1714         {
1715           GNUNET_break (0);
1716           break;
1717         }
1718       switch (ntohs (imm->type))
1719         {
1720         case GNUNET_MESSAGE_TYPE_TRANSPORT_ACK:
1721 #if DEBUG_TRANSPORT
1722           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1723                       "Receiving `%s' message from `%4s'.\n",
1724                       "ACK", GNUNET_i2s (&im->peer));
1725 #endif
1726           n = find_neighbour (h, &im->peer);
1727           if (n == NULL)
1728             {
1729               GNUNET_break (0);
1730               break;
1731             }
1732           if (n->received_ack == GNUNET_NO)
1733             {
1734               n->received_ack = GNUNET_YES;
1735               if (NULL != n->transmit_handle)
1736                 {
1737 #if DEBUG_TRANSPORT
1738                   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1739                               "Peer connected, scheduling delayed message for deliverery now.\n");
1740 #endif
1741                   schedule_request (n->transmit_handle);
1742                 }
1743             }
1744           break;
1745         default:
1746 #if DEBUG_TRANSPORT
1747           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1748                       "Received message of type %u from `%4s'.\n",
1749                       ntohs (imm->type), GNUNET_i2s (&im->peer));
1750 #endif
1751           if (h->rec != NULL)
1752             h->rec (h->cls, &im->peer, imm,
1753                     GNUNET_TIME_relative_ntoh (im->latency), ntohs(im->distance));
1754           break;
1755         }
1756       break;
1757     default:
1758       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1759                   _
1760                   ("Received unexpected message of type %u in %s:%u\n"),
1761                   ntohs (msg->type), __FILE__, __LINE__);
1762       GNUNET_break (0);
1763       break;
1764     }
1765 }
1766
1767
1768 struct ClientTransmitWrapper
1769 {
1770   GNUNET_CONNECTION_TransmitReadyNotify notify;
1771   void *notify_cls;
1772   struct GNUNET_TRANSPORT_TransmitHandle *th;
1773 };
1774
1775
1776 /**
1777  * Transmit message of a client destined for another
1778  * peer to the service.
1779  */
1780 static size_t
1781 client_notify_wrapper (void *cls, size_t size, void *buf)
1782 {
1783   struct ClientTransmitWrapper *ctw = cls;
1784   struct OutboundMessage *obm;
1785   struct GNUNET_MessageHeader *hdr;
1786   size_t ret;
1787
1788   if (size == 0)
1789     {
1790 #if DEBUG_TRANSPORT
1791       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1792                   "Transmission request could not be satisfied.\n");
1793 #endif
1794       if (NULL != ctw->notify)
1795         GNUNET_assert (0 == ctw->notify (ctw->notify_cls, 0, NULL));
1796       GNUNET_free (ctw);
1797       return 0;
1798     }
1799   GNUNET_assert (size >= sizeof (struct OutboundMessage));
1800   obm = buf;
1801   if (ctw->notify != NULL)
1802     ret = ctw->notify (ctw->notify_cls,
1803                        size - sizeof (struct OutboundMessage),
1804                        (void *) &obm[1]);
1805   else
1806     ret = 0;
1807   if (ret == 0)
1808     {
1809       /* Need to reset flag, no SEND means no SEND_OK! */
1810       ctw->th->neighbour->transmit_ok = GNUNET_YES;
1811       GNUNET_free (ctw);
1812       return 0;
1813     }
1814   GNUNET_assert (ret >= sizeof (struct GNUNET_MessageHeader));
1815   hdr = (struct GNUNET_MessageHeader *) &obm[1];
1816   GNUNET_assert (ntohs (hdr->size) == ret);
1817   GNUNET_assert (ret + sizeof (struct OutboundMessage) <
1818                  GNUNET_SERVER_MAX_MESSAGE_SIZE);
1819 #if DEBUG_TRANSPORT
1820   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1821               "Transmitting `%s' message with data for `%4s'\n",
1822               "SEND", GNUNET_i2s (&ctw->th->target));
1823 #endif
1824   ret += sizeof (struct OutboundMessage);
1825   obm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SEND);
1826   obm->header.size = htons (ret);
1827   obm->priority = htonl (ctw->th->priority);
1828   obm->peer = ctw->th->target;
1829   GNUNET_free (ctw);
1830   return ret;
1831 }
1832
1833
1834
1835 /**
1836  * Check if we could queue a message of the given size for
1837  * transmission.  The transport service will take both its
1838  * internal buffers and bandwidth limits imposed by the
1839  * other peer into consideration when answering this query.
1840  *
1841  * @param handle connection to transport service
1842  * @param target who should receive the message
1843  * @param size how big is the message we want to transmit?
1844  * @param priority how important is the message?
1845  * @param timeout after how long should we give up (and call
1846  *        notify with buf NULL and size 0)?
1847  * @param notify function to call when we are ready to
1848  *        send such a message
1849  * @param notify_cls closure for notify
1850  * @return NULL if someone else is already waiting to be notified
1851  *         non-NULL if the notify callback was queued (can be used to cancel
1852  *         using GNUNET_TRANSPORT_notify_transmit_ready_cancel)
1853  */
1854 struct GNUNET_TRANSPORT_TransmitHandle *
1855 GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle
1856                                         *handle,
1857                                         const struct GNUNET_PeerIdentity
1858                                         *target, size_t size,
1859                                         unsigned int priority,
1860                                         struct GNUNET_TIME_Relative timeout,
1861                                         GNUNET_CONNECTION_TransmitReadyNotify
1862                                         notify, void *notify_cls)
1863 {
1864   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1865   struct GNUNET_TRANSPORT_TransmitHandle *th;
1866   struct NeighbourList *n;
1867   struct ClientTransmitWrapper *ctw;
1868
1869   if (size + sizeof (struct OutboundMessage) >=
1870       GNUNET_SERVER_MAX_MESSAGE_SIZE)
1871     {
1872       GNUNET_break (0);
1873       return NULL;
1874     }
1875 #if DEBUG_TRANSPORT
1876   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1877               "Asking transport service for transmission of %u bytes to peer `%4s'.\n",
1878               size, GNUNET_i2s (target));
1879 #endif
1880   n = find_neighbour (handle, target);
1881   if ((n != NULL) && (n->transmit_handle != NULL))
1882     return NULL;                /* already have a request pending for this peer! */
1883   ctw = GNUNET_malloc (sizeof (struct ClientTransmitWrapper));
1884   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
1885   ctw->notify = notify;
1886   ctw->notify_cls = notify_cls;
1887   ctw->th = th;
1888   th->handle = handle;
1889   th->neighbour = n;
1890   th->target = *target;
1891   th->notify = &client_notify_wrapper;
1892   th->notify_cls = ctw;
1893   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1894   th->notify_size = size + sizeof (struct OutboundMessage);
1895   th->priority = priority;
1896   if (NULL == n)
1897     {
1898       pos = handle->connect_wait_head;
1899       while (pos != NULL)
1900         {
1901           GNUNET_assert (0 != memcmp (target,
1902                                       &pos->target,
1903                                       sizeof (struct GNUNET_PeerIdentity)));
1904           pos = pos->next;
1905         }
1906 #if DEBUG_TRANSPORT
1907       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1908                   "Will now try to connect to `%4s'.\n", GNUNET_i2s (target));
1909 #endif
1910       try_connect (th);
1911       return th;
1912     }
1913
1914 #if DEBUG_TRANSPORT
1915   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1916               "Transmission request queued for transmission to transport service.\n");
1917 #endif
1918   GNUNET_assert (NULL == n->transmit_handle);
1919   n->transmit_handle = th;
1920   if (GNUNET_YES != n->received_ack)
1921     {
1922 #if DEBUG_TRANSPORT
1923       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1924                   "Connection to `%4s' is not yet confirmed connected, scheduling timeout (%llu ms) only.\n",
1925                   GNUNET_i2s (target), timeout.value);
1926 #endif
1927       th->notify_delay_task
1928         = GNUNET_SCHEDULER_add_delayed (handle->sched,
1929                                         timeout, &peer_transmit_timeout, th);
1930       return th;
1931     }
1932
1933 #if DEBUG_TRANSPORT
1934   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1935               "Peer `%4s' is ready to receive, scheduling message for delivery now.\n",
1936               GNUNET_i2s (target));
1937 #endif
1938   th->notify_delay_task
1939     = GNUNET_SCHEDULER_add_now (handle->sched, &transmit_ready, th);
1940   return th;
1941 }
1942
1943
1944 /**
1945  * Cancel the specified transmission-ready notification.
1946  */
1947 void
1948 GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct
1949                                                GNUNET_TRANSPORT_TransmitHandle
1950                                                *th)
1951 {
1952   struct GNUNET_TRANSPORT_Handle *h;
1953
1954 #if DEBUG_TRANSPORT
1955   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1956               "Transmission request of %u bytes to `%4s' was cancelled.\n",
1957               th->notify_size - sizeof (struct OutboundMessage),
1958               GNUNET_i2s (&th->target));
1959 #endif
1960   GNUNET_assert (th->notify == &client_notify_wrapper);
1961   remove_from_any_list (th);
1962   h = th->handle;
1963   if ((h->connect_ready_head == NULL) && (h->network_handle != NULL))
1964     {
1965       GNUNET_CLIENT_notify_transmit_ready_cancel (h->network_handle);
1966       h->network_handle = NULL;
1967       h->transmission_scheduled = GNUNET_NO;
1968     }
1969   GNUNET_free (th->notify_cls);
1970   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1971   GNUNET_free (th);
1972 }
1973
1974
1975 /* end of transport_api.c */